Unit icons.

I'm working on a large mod that involves upscaling, recoloring textures, and replacing faces while preserving the original models.
The textures are all ready, but I'm facing an issue with the icons. Currently, the only idea I have is to take screenshots and manually crop them.
The problem is that the in-game lighting overexposes certain areas of the textures, resulting in a messy outcome.
Does anyone know a simple and straightforward way to create 170+ icons?